1. Field of the Invention:
This invention relates to an improved process for preparing 1,2,4,5-tetrachlorobenzene.
2. Description of the Prior Art:
The production of 1,2,4,5-tetrachlorobenzene from a Lewis acid-catalyzed contacting of 1,2,4-trichlorobenzene and chlorine gas is known. However, for each pound of desired isomer produced, about 0.5 pounds of undesired isomers and tars are also produced. This latter material has little or no utility whereas the former material is a precursor of 2,4,5-trichlorophenol, an intermediate to many valuable, biologically active compounds. Any improvement in the yield of the 1,2,4,5-isomer is therefore desirable.